In the United States one of the most common allergies is to ragweed pollen. Allergic patients sensitive to ragweed have been immunized by repeated injections of ragweed antigen. The injections are given subcutaneously. Because patients are allergic to the injected antigens, it has been necessary in clinical practice to administer a large number of small but increasing doses over an extended period of time. Further, even with this regimen, some patients cannot tolerate the injections because of their very high sensitivity to the injected ragweed antigens. It has therefore been desired to provide a means for increasing the effectiveness of preparations for use in treating ragweed sensitive patients. More specifically, it has been desired to reduce the allergenicity (IgE mediated reactions) of such preparations, while maintaining or improving the immunogenicity (ability to induce IgG antibody). Optimally, the patient would be immunized by giving a few large doses of the ragweed antigen, and the immunity would be maintained for several weeks or months without the need for additional injections. Heretofore, however, these objectives have not been achieved.
In the U.S. Pat. No. 3,794,630, there is disclosed a method for reacting protein allergenic extracts with dialdehydes such as glutaraldehyde. The resultant products which are said to be substantially water-insoluble are claimed to provide reduced allergenicity relative to the untreated allergen. The examples disclose the preparation of such water-insoluble polymerized products from extracts of Cocksfoot pollen and timothy pollen. There is no example or other reference to ragweed pollen.